Hydro excavation vacuum apparatus

ABSTRACT

Hydro excavation vacuum apparatus that process spoil material onboard the apparatus by separating water from the cut earthen material are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.16/630,057, filed Jan. 10, 2020, which is the 35 U.S.C. § 371 nationalstage of International Patent Application No. PCT/US2018/041934, filedJul. 13, 2018, which claims the benefit of U.S. Provisional ApplicationNo. 62/532,853, filed Jul. 14, 2017, each of which is incorporatedherein by reference in its entirety.

FIELD OF THE DISCLOSURE

The field of the disclosure relates to hydro excavation vacuum apparatusand, in particular, mobile excavating apparatus that process spoilmaterial onboard by separating water from the cut earthen material.

BACKGROUND

Hydro vacuum excavation involves directing high pressure water at anexcavation site while removing cut earthen material and water by avacuum system. Sites may be excavated to locate utilities or to cuttrenches. The spoil material is removed by entraining the spoil materialin an airstream generated by the vacuum system. The spoil material isstored on a vehicle for transport for later disposal of the spoilmaterial. Spoil material is conventionally landfilled or dumped at adesignated disposal site. Landfill disposal of spoil material containinga large amount of water may be relatively expensive. Further, tighteningregulations may limit disposal options for such slurries.

This section is intended to introduce the reader to various aspects ofart that may be related to various aspects of the disclosure, which aredescribed and/or claimed below. This discussion is believed to behelpful in providing the reader with background information tofacilitate a better understanding of the various aspects of the presentdisclosure. Accordingly, it should be understood that these statementsare to be read in this light, and not as admissions of prior art.

SUMMARY

One aspect of the present disclosure is directed to a hydro excavationvacuum apparatus for excavating earthen material. The apparatus includesa wand for directing pressurized water toward earthen material to cutthe earthen material. The wand includes a rotary nozzle for directingwater in a rotating, circular path toward the earthen material at anexcavation site. The apparatus includes a vacuum system for removing cutearthen material and water from the excavation site in an airstream. Theapparatus includes a separation vessel for removing cut earthen materialand water from the airstream. An airlock receives material from theseparation vessel and discharges the material through an airlock outlet.The apparatus includes a dewatering system for separating water from cutearthen material discharged from the airlock outlet. The dewateringsystem includes a pre-screen that receives material from the outlet ofthe airlock. The pre-screen has openings for separating material fromthe separation vessel by size. The dewatering system includes avibratory screen for separating material that passes through thepre-screen by size. The vibratory screen has openings sized smaller thanthe openings of the pre-screen.

Another aspect of the present disclosure is directed to a hydroexcavation vacuum apparatus for excavating earthen material. Theapparatus includes a wand for directing pressurized water toward earthenmaterial at an excavation site to cut the earthen material. Theapparatus includes a vacuum system for removing cut earthen material andwater from the excavation site in an airstream. The vacuum is capable ofgenerating a vacuum of at least 18″ Hg at 3000 cubic feet per minute.The apparatus includes a separation vessel for removing cut earthenmaterial and water from the airstream. An airlock receives materialdischarged from the separation vessel and discharges the materialthrough an airlock outlet. The apparatus includes a dewatering systemfor separating water from cut earthen material discharged from theairlock outlet. The dewatering system includes a pre-screen thatreceives material from the separation vessel. The pre-screen hasopenings for separating material from the separation vessel by size. Thedewatering system includes a vibratory screen for separating materialthat passes through the pre-screen by size. The vibratory screen hasopenings with a size smaller than the size of the openings of thepre-screen. A ratio of the size of the openings of the pre-screen to thesize of the openings of the vibratory screen is at least about 100:1.

Yet a further aspect of the present disclosure is directed to a hydroexcavation vacuum apparatus for excavating earthen material. Theapparatus includes a vacuum system for removing cut earthen material andwater from an excavation site in an airstream. The apparatus includes adeceleration system for collecting cut earthen material and water fromthe airstream. The deceleration system includes a deceleration vesseladapted to reduce a velocity of the airstream to allow material to fallfrom the airstream. The deceleration vessel has an inlet and a spoilmaterial outlet disposed below the inlet. The deceleration systemincludes a deflection plate disposed within the deceleration vessel fordirecting material in the airstream downward toward the spoil materialoutlet. The apparatus includes a dewatering system for separating waterfrom cut earthen material removed from the excavation site.

Yet another aspect of the present disclosure is directed to a vacuumexcavation apparatus for excavating earthen material. The apparatusincludes a vacuum system for removing cut earthen material from anexcavation site in an airstream. The apparatus includes a decelerationsystem for collecting cut earthen material from the airstream. Thedeceleration system includes a deceleration vessel adapted to reduce avelocity of the airstream to allow material to fall from the airstream.The deceleration vessel has a vertical axis and an inlet and a spoilmaterial outlet disposed below the inlet. The deceleration systemincludes a deflection plate disposed within the deceleration vessel fordirecting material in the airstream downward toward the spoil materialoutlet. The deflection plate has a material-engaging face having alongitudinal plane. The longitudinal plane of the material-engaging faceforms an angle with the vertical axis of the vessel.

Yet another aspect of the present disclosure is directed to a method forhydro excavating a site with an excavation apparatus. The excavationapparatus includes an excavation fluid pump, a separation vessel and adewatering system. The excavation fluid pump is operated to directpressurized water toward an excavation site. The pressurized water cutsearthen material. Cut earthen material and water are removed from theexcavation site in an airstream and into the separation vessel. The cutearthen material and water separate from the airstream and fall towardan airlock disposed below the separation vessel. The airstream has anaverage dwell time of less than about 5 seconds in the separationvessel. Material discharged from the airlock outlet is introduced intothe dewatering system. The dewatering system separates water from cutearthen material removed from the excavation site.

In a further aspect of the present disclosure, a hydro excavation vacuumapparatus for excavating earthen material includes a wand for directingpressurized water toward earthen material to cut the earthen material.An excavation fluid pump supplies fluid to the wand to cut the earthenmaterial. The apparatus includes a vacuum system for removing cutearthen material and water from the excavation site and a dewateringsystem for separating water from cut earthen material removed from theexcavation site. The apparatus includes a fluid storage and supplysystem which receives water from the dewatering system. The fluidstorage and supply system includes a first vessel in fluid communicationwith the excavation fluid pump and a first vessel level sensor forsensing the fluid level in the first vessel. The fluid storage andsupply system includes a second vessel. The second vessel is in fluidcommunication with the dewatering system to receive water dischargedfrom the dewatering system. The fluid storage and supply system includesa second vessel level sensor for sensing the fluid level in the secondvessel and a second vessel transfer pump for transferring fluid from thesecond vessel.

In another aspect of the present disclosure a hydro excavation vacuumapparatus for excavating earthen material includes a wand for directingpressurized water toward earthen material to cut the earthen material.An excavation fluid pump supplies fluid to the wand to cut the earthenmaterial. The apparatus includes a vacuum system for removing cutearthen material and water from the excavation site. The apparatusincludes a dewatering system for separating water from cut earthenmaterial removed from the excavation site. The apparatus includes afluid storage and supply system. The fluid storage and supply systemincludes a first vessel in fluid communication with the excavation fluidpump. The fluid storage and supply system includes a second vessel. Thesecond vessel is in fluid communication with the dewatering system toreceive fluid discharged from the dewatering system. The fluid storageand supply system includes a third vessel for receiving fluid from thesecond vessel.

An aspect of the present disclosure is directed to a method for hydroexcavating a site with an excavation apparatus having at least twovessels for supplying and storing excavation fluid. Maiden water isprovided in a first vessel of the apparatus. The maiden water is at aninitial level. Pressurized maiden water from the first vessel isdirected toward an excavation site. The pressurized water cuts earthenmaterial. Cut earthen material and first cycle water are removed fromthe excavation site. First cycle water is separated from the cut earthenmaterial. The first cycle water is introduced into a second vessel.Additional maiden water is introduced into the first vessel upon themaiden water level in the first vessel being reduced to below theinitial level or less.

In another aspect of the present disclosure directed to a hydroexcavation vacuum apparatus for excavating earthen material, theapparatus includes a wand for directing pressurized water toward earthenmaterial to cut the earthen material. An excavation fluid pump suppliesfluid to the wand to cut the earthen material. The apparatus includes avacuum system for removing cut earthen material and water from theexcavation site. The apparatus includes a dewatering system forseparating water from cut earthen material removed from the excavationsite. The apparatus includes a fluid storage and supply system whichreceives water from the dewatering system. The fluid storage and supplysystem includes a first vessel and a second vessel. The second vessel isin fluid communication with the dewatering system to receive waterdischarged from the dewatering system. The fluid storage and supplysystem includes a third vessel and a valving system for switching thesource of water directed through the wand from the first vessel to thesecond vessel.

Yet a further aspect of the present disclosure is directed to a methodfor hydro excavating a site with an excavation apparatus having at leasttwo vessels for supplying and storing excavation fluid. Maidenpressurized water from a first vessel is directed toward one or moreexcavation sites. The first vessel has a volume. The pressurized watercuts earthen material. The volume of maiden pressurized water used forexcavation is at least the volume of the first vessel. Cut earthenmaterial and first cycle water are removed from one more excavationsites. First cycle water is separated from the cut earthen material. Thefirst cycle water is introduced into a second vessel. Additional maidenpressurized water is directed toward one or more excavation sites afterthe volume of the maiden pressurized water used for excavation is atleast the volume of the first vessel.

In another aspect of the present disclosure directed to an airlock forconveying material, the airlock includes a plurality of rotatable vanesthat form pockets to hold and convey material. The vanes rotate from anairlock inlet to an airlock outlet along a conveyance path. The airlockincludes a housing. The housing has a first sidewall, a second sidewall,and an outer annular wall that extends from the first sidewall to thesecond sidewall. The airlock outlet extends through the outer annularwall. The airlock outlet tapers outwardly from a vertex toward at leastone sidewall.

In a further aspect of the present disclosure directed to a method forhydro excavating a site with an excavation apparatus, pressurized wateris directed toward an excavation site. The pressurized water cutsearthen material. Cut earthen material and water are removed from theexcavation site and into a separation vessel. The cut earthen materialand water separate from the airstream and fall toward an airlockdisposed below the separation vessel. The airlock has rotating vanesthat form pockets to receive cut earthen material and water. The airlockhas less than 10 vanes. The vanes of the airlock are rotated at a speedof less than 10 RPM to move cut earthen material and water from anairlock inlet toward an airlock outlet. Material discharged from theairlock outlet is introduced into a dewatering system. The dewateringsystem separates water from cut earthen material removed from theexcavation site.

Another aspect of the present disclosure is directed to a hydroexcavation vacuum apparatus for excavating earthen material. Theapparatus includes a wand for directing pressurized water toward earthenmaterial to cut the earthen material. The wand includes a rotary nozzlefor directing water in a rotating, circular path toward the earthenmaterial at an excavation site. The apparatus includes a vacuum pump forremoving cut earthen material and water from the excavation site in anairstream. The vacuum pump is a positive displacement pump. Theapparatus includes a separation vessel for removing cut earthen materialand water from the airstream. An apparatus includes a conduit forconveying water and cut earthen material from the excavation site to theseparation vessel. The conduit has a diameter D₁. An airlock receivesmaterial from the separation vessel and discharges the material throughan airlock outlet. The airlock includes vanes with pockets disposedbetween adjacent vanes. The vanes are sized to receive particles with adiameter D₁ or greater.

An additional aspect of the present disclosure is directed to a hydroexcavation vacuum apparatus for excavating earthen material at anexcavation site. The apparatus has a lateral axis and includes a wandfor directing pressurized water toward earthen material to cut theearthen material. The apparatus includes a vacuum system for removingcut earthen material and water from the excavation site in an airstream.The apparatus includes a separation vessel for removing cut earthenmaterial and water from the airstream. An airlock receives material fromthe separation vessel and discharges the material through an airlockoutlet. The apparatus includes a dewatering system for separating waterfrom cut earthen material. The dewatering system includes at least onescreen for separating material by size. The apparatus includes anadjustment system for adjusting a pitch or a roll of the screen. Theadjustment system includes an actuator for adjusting the pitch and/orthe roll of the screen and a pivot member for adjusting the pitch or theroll of the screen. The pivot member is aligned with the airlock outletrelative to the lateral axis.

An aspect of the present disclosure is directed to a hydro excavationvacuum apparatus for excavating earthen material at an excavation site.The apparatus has a longitudinal axis and includes a wand for directingpressurized water toward earthen material to cut the earthen material.The apparatus includes vacuum system for removing cut earthen materialand water from the excavation site in an airstream. The apparatusincludes a separation vessel for removing cut earthen material and waterfrom the airstream. An airlock receives material from the separationvessel and discharges the material through an airlock outlet. Theapparatus includes a dewatering system for separating water from cutearthen material. The dewatering system includes at least one screen forseparating material by size. The screen has a rear toward which materialis loaded onto the screen from the airlock outlet and a front towardwhich material is discharged from the screen. The screen has a centerplane midway between the rear and the front. The apparatus includes anadjustment system for adjusting a pitch or a roll of the screen. Theadjustment system includes an actuator for adjusting the pitch or theroll of the screen. The adjustment system includes a pivot member foradjusting the pitch and/or the roll of the screen. The pivot member isrearward to the center plane of the screen relative to the longitudinalaxis.

In yet another aspect of the present disclosure directed to a hydroexcavation vacuum apparatus for excavating earthen material, theapparatus has a longitudinal axis and includes a wand for directingpressurized water toward earthen material to cut the earthen material.The apparatus includes a vacuum system for removing cut earthen materialand water from the excavation site in an airstream. The apparatusincludes a separation vessel for removing cut earthen material and waterfrom the airstream. The apparatus includes an airlock that receivesmaterial from the separation vessel and discharges the material throughan airlock outlet. The apparatus includes a dewatering system forseparating water from cut earthen material. The dewatering systemincludes at least one screen for separating material by size. Anadjustment system for adjusting a pitch and a roll of the screenincludes an actuator for adjusting the pitch or the roll of the screen.The adjustment system includes a pivot member for adjusting the pitchand the roll of the screen. The pivot member includes a first portion toadjust the roll of the screen and a second portion to adjust the pitchof the screen.

Yet a further aspect of the present disclosure is directed to a cyclonicseparation system for separating material entrained in an airstream. Thesystem includes one or more cyclones for separating material from theairstream. The one or more cyclones have a solids outlet. The systemincludes a sealed conveyor with the one or more cyclones dischargingmaterial directly into the conveyor through the solids outlet. Thesystem includes a discharge pump with the sealed conveyor dischargingmaterial into the discharge pump.

Yet another aspect of the present disclosure is directed to a hydroexcavation vacuum apparatus for excavating earthen material. Theapparatus includes a wand for directing pressurized water toward earthenmaterial to cut the earthen material. An excavation fluid pump suppliesfluid to the wand to cut the earthen material. The apparatus includes avacuum system for removing cut earthen material and water from anexcavation site and includes a dewatering system for separating waterfrom cut earthen material removed from the excavation site. Theapparatus includes a fluid storage and supply system that receives waterfrom the dewatering system. The fluid storage and supply system includesa discharge manifold for offloading water from the fluid storage andsupply system. The system includes a first vessel and a second vessel.The second vessel is in fluid communication with the dewatering systemto receive water discharged from the dewatering system. The systemincludes a transfer pipe for transferring fluid from the first vessel toan excavation fluid pump. The system includes a valve for selectivelydirecting fluid from the first vessel between (1) the transfer pipe and(2) the discharge manifold.

Yet a further aspect of the present disclosure is directed to a methodfor filling a fluid storage and supply system of a hydro vacuumexcavation apparatus. The fluid storage and supply system includes afirst vessel, a second vessel for receiving water from a dewateringsystem, a third vessel, and a manifold connected to the first, secondand third vessels. Water is added to the first vessel. One or valves areactuated such that the first vessel is in fluid communication with themanifold and the third vessel is in fluid communication with themanifold. A first vessel transfer pump is operated to transfer waterfrom the first vessel, into the manifold and into the third vessel.

Various refinements exist of the features noted in relation to theabove-mentioned aspects of the present disclosure. Further features mayalso be incorporated in the above-mentioned aspects of the presentdisclosure as well. These refinements and additional features may existindividually or in any combination. For instance, various featuresdiscussed below in relation to any of the illustrated embodiments of thepresent disclosure may be incorporated into any of the above-describedaspects of the present disclosure, alone or in any combination.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side view of a hydro excavation vacuum apparatus;

FIG. 2 is a right side view of the hydro excavation vacuum apparatus;

FIG. 3A is a perspective view of the hydro excavation vacuum apparatus;

FIG. 3B is a schematic of water and air flow in the hydro excavationvacuum apparatus;

FIG. 3C is a detailed schematic view of the wand and wand nozzle;

FIG. 4 is a front view of a separation vessel, shown as a decelerationvessel, and an airlock;

FIG. 5 is a top view of the deceleration vessel and a deflection plate;

FIG. 6 is a side view of the deceleration vessel and airlock;

FIG. 7 is a perspective view of the deflection plate;

FIG. 8A is a perspective view of the airlock;

FIG. 8B is a cross-section side view of the airlock with a particlewithin a pocket thereof;

FIG. 9 is a perspective view of a dewatering system;

FIG. 10 is a perspective view of another embodiment of a dewateringsystem;

FIG. 11 is a cross-section side view of a flat wire belt conveyor of thedewatering system of FIG. 10;

FIG. 12 is a top view of the dewatering system of FIG. 9;

FIG. 13 is a top view of a pivot member for controlling the pitch androll of a screen of the dewatering system;

FIG. 14 is a detailed cross-section side view of the apparatus;

FIG. 15 is a detailed cross-section perspective view of the apparatus;

FIG. 16 is a block diagram of a system for controlling the pitch androll of a screen of the dewatering system;

FIG. 17 is a detailed perspective view of the apparatus;

FIG. 18 is a side view of a fluid storage and supply system;

FIG. 19 is a side view of the fluid storage and supply system with threevessels full of maiden water;

FIG. 20 is a side view of the fluid storage and supply system afterexcavation has commenced;

FIG. 21 is a side view of the fluid storage and supply system with anamount of maiden water transferred from the third vessel and fourthvessel;

FIG. 22 is a side view of the fluid storage and supply system with thethird vessel emptied of maiden water;

FIG. 23 is a side view of the fluid storage and supply system with firstcycle water transferred from the second vessel to the third vessel;

FIG. 24 is a side view of the fluid storage and supply system with firstcycle water being transferred from the third vessel into the fourthvessel;

FIG. 25 is a side view of the fluid storage and supply system with thesecond, third, and fourth vessels filled with first cycle water;

FIG. 26 is a schematic view of a two vessel fluid storage and supplysystem;

FIG. 27 is a schematic view of a three vessel fluid storage and supplysystem;

FIG. 28 is a block diagram of a system for controlling the transfer offluid in the fluid storage and supply system;

FIG. 29 is a block diagram of a valving system for controlling thetransfer of fluid in the fluid storage and supply system;

FIG. 30 is a perspective view of a cyclonic separation system;

FIG. 31 is a perspective view of a cyclonic separation system showingthe screws of the conveyors;

FIG. 32 is a side view of the cyclonic separation system;

FIG. 33 is a perspective view of the cyclonic separation system showingthe screw and motor of a conveyor removed from the conveyor housing;

FIG. 34 is a cross-section view of the cyclonic separation system;

FIG. 35 is a side view of a peristaltic pump;

FIG. 36 is a side view of a roller of the peristaltic pump in aretracted position;

FIG. 37 is a side view of the cyclonic separation system as part of ahydro excavation vacuum apparatus;

FIG. 38 is another embodiment of a fluid storage and supply system;

FIG. 39 is a cross-section of a vessel of the fluid storage and supplysystem;

FIG. 40 is a cross-section of an airgap device;

FIG. 41 is a bottom view of the fluid storage and supply system; and

FIG. 42 is a side view of a valve of the fluid storage and supplysystem.

Corresponding reference characters indicate corresponding partsthroughout the drawings.

DETAILED DESCRIPTION

An example hydro excavation vacuum apparatus 3 for excavating earthenmaterial is shown in FIG. 1. As described in further detail herein, thehydro excavation vacuum apparatus 3 is used to excavate a site by use ofa jet of high pressure water expelled through a wand. The cut earthenmaterial and water are removed by a vacuum system and are processedonboard the apparatus by separating the cut earthen material from thewater. Processed water may suitably be used for additional excavation ordisposed. Recovered earthen material may be used to backfill theexcavation site or disposed.

The hydro excavation vacuum apparatus 3 may include a chassis 14 whichsupports the various components (e.g., vacuum system, separation vessel,airlock and/or dewatering system) with wheels 16 connected to thechassis 14 to transport the apparatus 3. The apparatus 3 may beself-propelled (e.g., with a dedicated motor that propels the apparatus)or may be adapted to be towed by a separate vehicle (e.g., may include atongue and/or hitch coupler to connect to the separate vehicle).

The hydro excavation vacuum apparatus 3 includes a dedicated engine 26that powers the various components such as the excavation pump, vacuumpump, vibratory screens, conveyors and the like. In other embodiments,the engine 26 is eliminated and the apparatus is powered by a motor thatpropels the apparatus or the apparatus 3 is powered by other methods.

The apparatus 3 includes a front 10, rear 18, and a longitudinal axis A(FIG. 3A) that extends through the front 10 and rear 18 of the apparatus3. The apparatus 3 includes a lateral axis B that is perpendicular tothe longitudinal axis A.

High Pressure Excavation and Vacuum System

The hydro excavation vacuum apparatus 3 includes a wand 4 (FIG. 3B) fordirecting pressurized water W toward earthen material to cut the earthenmaterial. The wand 4 is connected to an excavation fluid pump 6 thatsupplies water to the wand 4. The pump 6 may supply a pressure of, forexample, at least about 500 psi or at least about 1,000 psi (e.g., fromabout 1,000 psi to about 5,000 psi or from 1,000 psi to about 3,000psi).

In some embodiments, the wand 4 includes a rotary nozzle 8 (FIG. 3C) fordirecting water W toward the earthen material to cut the earthenmaterial. Generally, any rotary nozzle that causes the water to bedirected toward the earthen material in a circular path at the site ofthe excavation may be used. Such rotary nozzles may include a rotorinsert with blades that rotate around a longitudinal axis of the nozzlewhen water is forced through the nozzle. The rotor insert may includethree or more channels that force fluid to flow in different pathwaysthrough the rotor insert to cause the water to move along a circularpath as it contacts the excavation material (i.e., the water moveswithin a cone that extends from the nozzle toward the excavatedmaterial). In other embodiments, a straight tip nozzle that directsfluid along a straight path in a concentrated jet may be used.

The hydro excavation vacuum apparatus 3 includes a vacuum system 7(FIG. 1) for removing spoil material from the excavation site. Spoilmaterial or simply “spoils” may include, without limitation, rocks, cutearthen material (e.g., small particulate such as sand to larger piecesof earth that are cut loose by the jet of high pressure water), slurry,and water used for excavation. The spoil material may have a consistencysimilar to water, a slurry, or even solid earth or rocks. The terms usedherein for materials that may be processed by the hydro excavationvacuum apparatus 3 such as, for example, “spoils,” “spoil material,”“cut earthen material” and “water”, should not be considered in alimiting sense unless stated otherwise.

The vacuum system 7 includes a boom 9 that is capable of rotating towardthe excavation site to remove material from the excavation site. Theboom 9 may include a flexible portion 5 (FIG. 3B) that extends downwardto the ground to vacuum spoil material from the excavation site. Theflexible portion 5 may be manipulated by a user to direct the vacuumsuction toward the excavation site.

The vacuum system 7 acts to entrain the cut earth and the water used toexcavate the site in a stream of air. A blower or vacuum pump 24 (FIG.3B) pulls a vacuum through the boom 9 to entrain the material in theairstream. Air is discharged from the blower 24 after material isremoved from the airstream.

The airstream having water and cut earth entrained therein is pulledthrough the boom 9 and through a series of conduits (e.g., conduit 47shown in FIG. 6) and is pulled into a separation vessel 21, describedfurther below. The separation vessel 21 removes at least a portion ofcut earthen material and water from the airstream. Air exits one or moreseparation vessel air outlets 49 and is introduced into cyclones 11(FIG. 2) to remove additional spoil material (e.g., water, small solidssuch as sand, low density particles such as sticks and grass, and thelike) not separated in the separation vessel 21. Material that collectsin the bottom of the cyclones 11 is conveyed by a cyclone discharge pump20 (FIG. 1) (e.g., peristaltic pump described in further detail below)or, alternatively, is gravity fed to the dewatering system 95 describedbelow. The air removed from the cyclones 11 is introduced into one ormore filter elements before entering the vacuum pump 24. The vacuum pump24 may be disposed in or near the engine compartment 26 (FIG. 1). Air isremoved from the apparatus through a vacuum exhaust 29.

The vacuum pump 24 generates vacuum in the system to pull water and cutearthen material into the apparatus 3 for processing. In someembodiments, the vacuum pump 24 is a positive displacement pump. Suchpositive displacement pumps may include dual-lobe or tri-lobe impellers(e.g., a screw rotor) that draw air into a vacuum side of the pump andforces air out the pressure side. In some embodiments, the pump iscapable of generating a vacuum of at least 18″ Hg and/or a flow rate ofat least about 3000 cubic feet per minute. The pump may be powered by amotor having a power output of, for example, at least 75 hp, at least100 hp or even at least 125 hp.

Separation System for Removing Spoil Material from the Airstream

The separation vessel 21 and cyclones 11 are part of a separation system46 for removing spoil material from the airstream. The separation vessel21 is a first stage separation in which the bulk of spoil material isremoved from the airstream with carryover material in the airstreambeing removed by the cyclones 11 in a second stage (i.e., the separationvessel 21 is the primary separation vessel with the downstream cyclones11 being secondary separation vessels).

Spoil material containing water and cut earth is introduced into theseparation vessel 21 through inlet conduit 47 (FIG. 6). At least aportion of spoil material falls from the airstream to a spoil materialoutlet 33 and into an airlock 55. Air removed through air outlets 49 isprocessed in cyclones 11 (FIG. 2) to remove at least a portion ofcarryover spoil material.

Typically the particle size of spoils entering the cyclones 11 will besmaller than spoil particles removed by the separation vessel 21. Spoilsremoved from the air by the cyclones 11 are typically fluidic. Spoilmaterial removed by the cyclones 11 is fed by the cyclone discharge pump20 (FIG. 1) to the dewatering system 95 described further below (e.g.,directly to a vibratory screen). Air exiting the cyclones 11 passesthrough a filter element before entering the vacuum pump 24 (FIG. 3B).The air is pulled through the vacuum pump 24 and exits the apparatusthrough the air exhaust 29.

The separation vessel 21 has an inlet 31 (FIG. 5) and a spoil materialoutlet 33 disposed below the inlet 31. An air outlet 49 (FIG. 6) isdisposed above the inlet 31. In the illustrated embodiment, theseparation vessel 21 includes a plurality of air outlets 49. In otherembodiments, the separation vessel 21 may include a single air outlet49. The outlets 49 are fluidly connected to the cyclones 11 (FIG. 2) toseparate material that remains entrained in the airstream withdrawn fromthe outlets 49.

The cyclones 11 may be part of a cyclonic separation system 67 (FIG. 1).As shown in FIG. 1, the cyclonic separation system 67 includes thecyclones 11 and the cyclone discharge pump 20. In the embodimentillustrated in FIG. 1, the cyclone discharge pump is a peristaltic pumpthat is connected to the cyclone discharge 76 by conduits (e.g., hosesor ducts). An example peristaltic pump 20 is shown in FIG. 35 describedfurther below.

Another embodiment of the cyclonic separation system 67 is shown inFIGS. 30-34. The cyclones 11 receive airflow from the separation vesseloutlets 49 (FIG. 4) through cyclone inlets 70 (FIG. 32). Cyclonic actionin the cyclones 11 causes entrained material to fall to the cyclonesolids outlet 76 (FIG. 31). It should be noted that “solids outlet”should not be considered in a limiting sense and any type of materialmay fall through the solids outlet 76 (e.g., water, mud, sand, sticks,etc.). Air is pulled through the cyclones 11 and is discharged throughcyclone discharge manifolds 78A, 78B and is directed to one or morefilter elements before entering the vacuum pump 24 (FIG. 3B).

The cyclone solids outlets 76 should be sized to reduce or preventbridging of granular material that passes through the outlets 76. Thecyclone solids outlets 76 are fluidly connected to conveyors 80A, 80B(e.g., the outlets 76 are formed in the conveyor housing 98). Theconveyors 80A, 80B are sealed to reduce or prevent air from entering thevacuum system through the conveyors 80A, 80B (e.g., having gaskets orbearings or the like that seal the conveyor from the ambientatmosphere). In the illustrated embodiment, the conveyors 80A, 80B arescrew conveyors (e.g., an auger) having a rotating screw 82A, 82B (FIG.31). As shown in FIG. 31, the screw conveyor may be a centerless screwconveyor (i.e., lacking a center shaft). In other embodiments, the screwconveyor may include a center shaft. In yet other embodiments, the oneor more conveyors 80 may be slat conveyors, belt conveyors or rotaryvane conveyors.

The conveyors 80 are powered by motors 80A, 80B which may bequick-attach motors to facilitate clean-out of the conveyors 80. Theconveyors 80 include access clamps 96 (FIGS. 30-32) that may be openedto allow the motors 86 and screw 82 to be removed the conveyor housing98 (FIG. 34) as shown in FIG. 33. The conveyor screw 82 may be connectedto the motor 86 to allow both the motor and screw to be removed from theconveyor housing as a single piece.

The longitudinal axis A₈₀ (FIG. 30) of the conveyors 80A, 80B isgenerally orthogonal to the longitudinal axis A₁₁ of the cyclones 11.The conveyors 80 may be sized and shaped to allow the conveyor to acceptsurges of material relatively quickly to reduce or prevent bridging ofmaterial through cyclone outlets 76. As shown in FIG. 34, the conveyorscrew 82 may be off-center with the center of the screw 82 being closerto the bottom of the housing 98 (FIG. 34) (i.e., the screw 82 isundersized compared to the housing 98).

The cyclonic separation system 67 may generally include any number ofcyclones 11 and conveyors 80 (e.g., one conveyor, two conveyors or moreand/or at least one cyclone, at least two, at least three, at leastfour, at least five, at least six or more cyclones 11). The cyclonicseparation system 67 generally does not include an airlock unless statedotherwise.

The conveyors 80 convey material toward conveyor outlets 84A, 84B (FIG.31) where the material is discharged into the cyclone discharge pump 20.In some embodiments, the cyclone discharge pump 20 is a peristalticpump. The peristaltic pump 20 seals the system 67 by reducing the amountof air that may enter the system 67. Referring now to FIG. 35, suchperistaltic pumps may include a plurality of rollers 88 that rotateabout the pump. The rollers 88 compress a hose or tube 90 in successionas they rotate to push material through a pump outlet 94. In theillustrated embodiment, the pump 20 includes four rollers 88. In otherembodiments, more or less than four rollers 88 may be used. The rollers88 may be configured to retract as shown in FIG. 36 (e.g., as when thepump 20 is not in operation). Configuring the rollers 88 to retractwhile not in operation allows the pump 20 to receive material that isdischarged from the cyclones 11 during storage and transportation.Retraction of the rollers 88 also assists in winterization, cleaning,and replacement of the tube 90 and may extend the life of the tube 90.

The rollers 88 may pivot about a pivot pin 97 to retract with a biasingelement 99 (e.g., spring) biasing the rollers in an extended position.Retraction of the rollers 88 may be automated by configuring the pump toreverse to cause the rollers 88 to retract when the pump 20 is switchedoff.

In the embodiment of FIG. 35, material may fall by gravity through thepump inlet 93 and into the hose 90. Material discharged from the pump 20is conveyed to the dewatering system 95 (FIG. 37) through outlet 94.

The cyclonic separation system 67 may be part of the hydro excavationvacuum apparatus 3 as shown in FIG. 37 or may be used in otherapplications such as in reclaimers (e.g., drill fluid reclaimers).

The separation vessel 21 includes an upper portion 51 (FIG. 4) having asidewall 56 and one or more air outlets 49 formed in the sidewall 56.The vessel 21 includes a lower portion 57 that tapers to the spoilmaterial outlet 33 (FIG. 5). The upper portion 51 and lower portion 57may be adapted (e.g., shaped), at least in part to ease manufacturing,for fit-up and for minimizing the potential for creating internalsurface features where material could set and build-up in the innersurfaces of the separation vessel 21.

In the illustrated embodiment, the lower portion 57 is conical. Theconical lower portion 57 may be arranged (e.g., with a sufficient slope)to reduce potential for cut earthen material to collect on the lowerportion 57. The illustrated lower portion 57 of the separation vessel 21has a circular, cross-section to eliminate internal corners wherecuttings may set and build-up. In other embodiments, the lower portion57 may have a non-circular cross-sectional profile. For example, thelower portion 57 may include a generally square profile with relativelylarge fillets at each corner. In the illustrated embodiment, the upperportion 51 has a circular or generally circular cross-section. The upperportion 51 may be cylindrical to ease the transitioning to the conicallower portion 57.

The inlet 31 extends through the conical lower portion 57. In otherembodiments, the inlet extends through the upper portion 51. The vessel21 has a central vertical axis D (FIG. 6).

The separation vessel 21 may be sized to reduce the dwell time ofmaterial in the vessel. The dwell time (DT) may be determined from thefollowing formula:

DT=Vol/Q

where Vol is the open volume of the vessel (i.e., volume not taken up byspoil material) and Q is the volumetric rate (e.g., actual CFM) at whichair is pulled by the vacuum system 7. In some embodiments, the dwelltime may be less than 5 seconds, less than 3 seconds or less than 1second (at standard cubic feet). Dwell time

In some embodiments, the apparatus 3 includes a single separation vessel21 in the first stage removal of solids and water from the airstream. Inother embodiments, two or more separation vessels 21 are operated inparallel in the first stage removal of solids and water from theairstream. In some embodiments, the separation vessel 21 processes from0.5 ft³ of spoil material per minute to 2.5 ft³ of spoil material perminute.

In the illustrated embodiment, the separation vessel 21 is adeceleration vessel in which the velocity of the airstream is reducedcausing material to fall from the airstream toward a bottom of theseparation vessel 21. The deceleration vessel 21 may be part of adeceleration system 23 (FIG. 4) for removing material from the airstreamby gravity.

The deceleration vessel 21 is adapted to allow material to fall from theairstream by gravity rather than by vortexing of air within the vessel21. In some embodiments, the inlet 31 of the vessel 21 is arranged suchthat the airstream does not enter the vessel 21 tangentially. Forexample, as shown in FIGS. 5 and 6, the inlet conduit 47 (and inlet 31)may have a longitudinal axis E that passes through the central verticalaxis D of the deceleration vessel 21. In other embodiments, thelongitudinal axis E is separated a relatively small amount from thecentral vertical axis D of the deceleration vessel 21 (e.g., by adistance less than 33% of the radius of vessel 21 or a distance lessthan 25%, 15%, 10% or 5% of the radius of the vessel 21).

To allow material to fall from the airstream, the deceleration vessel 21may have an effective cross-sectional area (i.e., cross-sectional areaof void space) larger than the cross-sectional area of the inlet conduit47 to reduce the velocity of the airstream in the vessel 21. Forexample, the ratio of the effective cross-sectional area of thedeceleration vessel 21 to the effective cross-sectional area of theinlet conduit 47 may be at least about 7.5:1 or, as in otherembodiments, at least about 10:1, at least about 15:1 or even at leastabout 20:1 to reduce the velocity of the airstream to allow material tofall from the airstream.

In the illustrated embodiment in which the deceleration vessel 21 andinlet conduit 47 are circular, the effective cross-sectional area of thedeceleration vessel 21 is proportional to the squared radius of theupper portion 51 of the deceleration vessel 21 and the effectivecross-sectional area of the inlet conduit 47 is proportional to thesquared radius of the inlet conduit 47. In some embodiments, the ratioof the radius of the deceleration vessel 21 to the radius of the inletconduit may be at least about 3:1, at least about 4:1, or even at leastabout 5:1.

The deceleration system 23 also includes a deflection plate 27 disposedwithin the deceleration vessel 21. The deflection plate 27 is configuredand positioned to cause spoil material entrained in the airstream tocontact the plate 27 and be directed downward toward the spoil materialoutlet 33. The deflection plate 27 includes a material-engaging face 39(FIG. 6) configured to contact material entrained in the airstream. Theface 39 has a longitudinal plane F and the plane F forms an angle λ withthe vertical axis D of the vessel 21. In some embodiments, the angle λbetween the longitudinal plane F of the material-engaging face 39 of thedeflection plate 27 and the vertical axis D of the vessel 21 may be fromabout 5° to about 75° or from about 5° to about 60°.

As shown in FIG. 6, the longitudinal axis E of the inlet conduit 47 (andinlet 31) may intersect the deflection plate 27. Alternatively or inaddition, the central vertical axis D may intersect the deflection plate27 or the plate may be forward or rearward to the central vertical axisD (e.g., forward or rearward up to 10% of the radius or forward orrearward up to 25%, 50% or 75% of the radius of the vessel).

In some embodiments and as shown in FIG. 7, the deflection plate 27includes a wear plate 41 connected to a support 43 to allow the wearplate 41 to be replaced upon the plate 41 becoming worn. The wear plate41 may be made of an abrasion resistant material including steel (e.g.,AR400 abrasion resistant steel) or abrasion resistant plastics.

In other embodiments, a separation vessel 21 using cyclonic separation(i.e., a cyclone) in which airflow travels in a helical pattern is usedto remove material from the airstream.

Airlock

An example airlock 55 is shown in FIGS. 6 and 8A. The airlock 55includes a plurality of rotatable vanes 59 connected to a shaft 61. Thevanes 59 rotate along a conveyance path in the direction shown by arrowR in FIG. 6. The shaft 61 is connected to a motor 58 (FIG. 4) thatrotates the shaft 61 and vanes 59. The airlock 55 has an airlock inlet69 through which material passes from the deceleration vessel 21 and anairlock outlet 71 through which water and cut earthen material aredischarged.

The airlock 55 includes a housing 63 (FIG. 8A) with the vanes 59rotating within the housing 63. The housing 63 includes a first sidewall85, a second sidewall 87, and an outer annular wall 81 that extendsbetween the first sidewall 85 and the second sidewall 87.

The vanes 59 include a main portion 75 and an outer wear strip 77 thatis connected to the main portion 75 by fasteners 79. The outer wearstrip 77 extends toward the outer annular wall 81 of the housing 63.During rotation, there may be a small gap between the wear strip 77 andthe outer annular wall 81 of the housing 63. Material may lodge betweenthe wear strip 77 and the annular wall 81 causing the wear strip towear. As the strip 77 wears, it may be adjusted outward (e.g., by use ofslots in the strip 77 through which the fasteners 79 extend).Alternatively, the strip 77 may be replaced when it is worn out or nolonger functional.

Air may pass from the ambient environment, through the gaps between thevanes 59 or wear strips 77 and the outer annular wall 81 and into thevacuum system 7 (FIG. 1). In other embodiments, the vanes 59 contact theouter annular wall 81 (e.g., as with wiper vanes) to more fully seal airfrom the vacuum system 7.

As shown in FIG. 8A, the airlock outlet 71 has a vertex 83. Proceedingin the direction of rotation of the vanes 59, the airlock outlet 71tapers outwardly from the vertex 83 toward at least one sidewall 85, 87.In the illustrated embodiment, the outlet 71 tapers from the vertex 83toward the first sidewall 85 and tapers from the vertex 83 toward thesecond sidewall 87 (i.e., proceeding in the direction of rotation of thevanes, the first portion of the outlet 71 is triangular in shape). Theoutlet 71 may taper toward the sidewalls 85, 87 in a straight path asshown or, as in other embodiments, in a curved path.

As shown in FIG. 4, the outer annular wall 81 has a center plane H thatis midway between the first and second sidewalls 85, 87. In theillustrated embodiment, the vertex 83 is at the center plane H.

Alternatively or in addition, the vanes 59 may taper to allow a smallopening to be exposed to the ambient as the vanes rotate.

Two adjacent vanes 59 collectively form a pocket 89 (FIG. 6) whichreceives spoil material. The airlock 55 may also include pocketsidewalls 91 (FIG. 8A) that contact and rotate with the vanes 59. Inother embodiments, the airlock 55 does not include pocket sidewalls 92.

In some embodiments, the airlock has less than about 15 vanes, less thanabout 10 vanes or about 8 vanes or less. In some embodiments, the vanes59 rotate at a speed of less than about 15 RPM or less than about 10 RPMor even less than about 5 RPM.

The number of vanes 59 and the diameter of the airlock 55 are selectedin some embodiments so that the pocket 89 may accommodate the largestsize of cut earthen material that may travel through the vacuum system 7to the separation vessel 21. Generally, the largest material that couldreach the airlock is material with a diameter equal to the diameter D1of the conduits through which air and cut earthen material travel to theseparation vessel 21. In some embodiments, the vanes 59 are sized toreceive particles P with a diameter D1 (FIG. 8B) or greater. Forexample, in some embodiments, the vane pockets 89 may have a depth d ofD1 or more. Alternatively or in addition, the pocket 89 may have width wof D1 or more at a mid-point MP of the pocket, the mid-point MP beingmidway between a top 72 and bottom 74 of the pocket 89.

Water and cut earth that exits the airlock 55 through the airlock outlet71 (FIG. 8A) is introduced into the dewatering system 95 describedfurther below (e.g., may be gravity fed to the dewatering system 95 asshown in the illustrated embodiments). In some embodiments, the waterand cut earthen material is directly introduced into the dewateringsystem 95 (e.g., directly fed to a screening system without intermediateprocessing).

Dewatering System

The dewatering system 95 (FIG. 9) of some embodiments includes apre-screen 101 that first engages material discharged from the outlet 71of the airlock 55. In the illustrated embodiment, the pre-screen 101 hasa plurality of slats 103 with openings formed between slats 103 throughwhich material falls. The pre-screen 101 may have relatively largeopenings (e.g., at least about 0.5 inches, at least about 1 inch, atleast about 1.5 inches, or 2 inches or more) such that relatively largematerial is prevented from passing through the pre-screen 101. The slats103 have ribs 105 which reinforce the slats 103.

The pre-screen 101 may be adapted to withstand the impact of largestones and earthen material that are capable of being removed by thevacuum system 7 (FIG. 1). Example screens include screens that may bereferred to by those of skill in the art as a “grizzly screener” orsimply “grizzly.” The pre-screen 101 may vibrate or, as in otherembodiments, does not vibrate.

The dewatering system 95 of this embodiment includes a vibratory screen109, more commonly referred to as a “shaker”, that separates materialthat passes through the pre-screen 101 by size. The vibratory screen 109has openings with a size smaller than the size of the openings of thepre-screen 101. In some embodiments, the size of the openings of thevibratory screen 109 are less than 250 micron, less than about 150micron or less than about 100 micron. The ratio of the size of theopenings of the pre-screen 101 to the size of the openings of thevibratory screen 109 may be at least about 100:1, at least about 250:1,or even at least about 500:1. The listed size of the openings and ratiosthereof are exemplary and other ranges may be used unless statedotherwise.

The vibratory screen 109 may be part of a shaker assembly 113. Theshaker assembly 113 includes vibratory motors 117 that cause the screen109 to vibrate. The shaker assembly 113 may be configured to move thevibratory screen 109 linearly or in an elliptical path (e.g., byarranging the number of motors, orientation of the motors, and/orplacement of the motors to move the vibratory screen 109 linearly or inan elliptical path).

The shaker assembly 113 rests on isolators 129 (shown as air bags) toisolate the vibratory movement of the assembly 113 from the chassis orframe to which it is connected. In some embodiments, the screen 109 isdivided into multiple segments that can separately be changed out formaintenance.

As the screen 109 vibrates, effluent falls through openings within thescreen 109 and particles that do not fit through the openings vibrate tothe discharge end 121 of the assembly 113. Solids that reach thedischarge end 121 fall into a hopper 125 (FIG. 1) and may be conveyedfrom the hopper 125 by a conveyor assembly 127 to form a stack ofsolids. Solids may be loaded into a bin, dumpster, loader bucket, groundpile, roll-off bin, dump truck or the like or may be conveyed to thesite of the excavation as backfill. Solids may be transported off of theapparatus 3 by other methods.

In some embodiments, the apparatus 3 does not include a mixer for mixingspoil material (e.g., for mixing solids to promote drying or for mixingin drying agents).

Liquid that passes through the vibratory screen 109 collects in acatchpan 112 (FIG. 14) and is conveyed by a return water pump 110 to thefluid storage and supply system 25 described more fully below.

Another example dewatering system 95 is shown in FIG. 10. The dewateringsystem 95 includes a flat wire belt conveyor 133. Such flat wire beltconveyors 133 may include spaced wires or rods which form an open meshin the belt that allow for liquids and particles that fit through themesh openings to pass through the mesh. The flat wire belt conveyor 133may remove larger solids and un-hydrated soil clumps which helps preventdownstream separation units from blinding (e.g., pluggage of meshopenings) and abrasive wear and damage. In various embodiments, the meshsize of the belt may be from about 0.25 cm to about 5 cm or from about0.5 cm to about 3 cm.

The flat wire belt conveyor 133 angles upward toward the rear 18(FIG. 1) of the apparatus 3 to promote separation of water from the cutearthen material. Liquid and small solids that pass through the meshbelt 137 (FIG. 11) fall through the top course 137A of the belt, land onthe bottom course 137B of mesh (i.e., the return) and fall through thebottom course of mesh onto a conveyor floor or “chute” 141. The belt 137may rest on the conveyor floor 141 and scrape material toward the liquiddischarge end of the flat wire belt conveyor 133. Solids that do notpass through the openings are carried forward by the belt 137. While thebelt 137 is shown of solid, unperforated material in the Figures forsimplicity, it should be understood that, in this embodiment, the belt137 includes mesh openings throughout the top course 137A and bottomcourse 137B. The flat wire belt conveyor 133 may include a series ofdeflectors 145 that act to turn or otherwise redirect solids that aremoving forward on the conveyor 133. By turning the solids, additionalfluid may fall through the conveyor 133 and be recovered as effluent.

The effluent that passes through the flat wire belt conveyor 133 isconveyed down the conveyor floor 141 and falls onto a shaker assembly159 (FIG. 10) having a vibratory screen 109. The shaker assembly 159 maybe configured similar to shaker assembly 113 described above anddescription herein of the shaker assembly 113 should be considered toapply to shaker assembly 159 unless stated otherwise. The shakerassembly 159 includes one or more vibratory screens 109 through whichliquid and fine solids pass. The shaker assembly 159 includes a firstside 159A which processes material that passes through and the flat wirebelt conveyor 133 and a second side 159B which processes materialseparated by cyclones 11 (FIG. 2). The openings of the flat wire beltconveyor 133 are generally larger than the openings of the shakerassembly 159 such that the second shaker assembly 159 separates finersolids.

The dewatering system 95 of the present disclosure may includeadditional separation and/or purification steps for processing cutearthen material. In some embodiments, the cut earth is separated fromwater only by use of a (1) a first stage pre-screen or flat wire beltconveyor, and (2) a second stage vibratory screen. In these or in otherembodiments, the screen (e.g., pre-screen 101 or flat wire belt conveyor133) may receive spoil material directly from the separation vessel 21without intermediate processing, i.e., without feeding the material to ahydrocyclone such as a desilter cone to separate water from earthenmaterial. In some embodiments, water that passed through the screens maybe fed directly to the water supply and storage system 25 (FIG. 1)described further below without being further processed (e.g.,centrifugation). In some embodiments, the water recovered from theexcavation site is not treated without additives (e.g., flocculantsand/or coagulants).

Pitch and Roll Adjustment System

The hydro excavation vacuum apparatus 3 may include an adjustment system148 (FIG. 12) for adjusting a pitch and a roll of one or more screens ofthe dewatering system 95. The adjustment system 148 may generally beused to adjust any screen such as the pre-screen 101, vibratory screen109 or flat wire belt conveyor 133 (FIG. 10) or to adjust combinationsof these screens.

The adjustment system 148 includes a pivot member 150 for adjusting thepitch and the roll of the screen. The screens pivot about a pitch axis P(FIG. 12) and also pivot about a roll axis R. The pivot member 150 ispivotally connected to a bracket 155 (FIG. 15) which is connected to thechassis 14 of the apparatus 3. In the illustrated embodiment, a singlepivot member 150 is shown. In other embodiments, two separate pivotmembers 150 are used.

Referring now to FIG. 13, the pivot member 150 includes a first portion160 to adjust the roll of the screen and a second portion 163 thatextends from the first portion 160 to adjust the pitch of the screen.The first portion 160 of the pivot member 150 is perpendicular to thesecond portion 163.

The pivot member 150 includes sleeves, bearings and/or bushings to allowthe screen to pivot with respect to the remainder of the apparatus. Inthe illustrated embodiment, the first portion 160 contains a firstportion sleeve 162 and a first shaft 166 that extends through the sleeve162. The first portion sleeve 162 is attached to a frame 152 (FIG. 15)that supports the screens to allow the frame 152 and screens to pivotabout the shaft 166 to adjust the roll of the screens. The secondportion 163 includes a second portion sleeve 168. The first shaft 166 isattached to the second portion sleeve 168. A second shaft 164 extendsthrough the second portion sleeve 168 and is connected to the bracket155 (FIG. 15). The second sleeve 168 and the screens pivot about theshaft 164 to adjust the pitch of the screens. In other embodiments, eachof the first and second portions 160, 163 may include a bushing orbearing such as a ball bearing or roller bearing.

The adjustment system 148 includes a first actuator 154A (FIG. 9) and asecond actuator 154B (shown as hydraulic cylinders) which work incooperation with the pivot member 150 to adjust the pitch and roll ofthe vibratory screen 109. A sensor 158 (FIG. 16) senses the pitch and/orroll of the screen. In other embodiments, two separate sensors detectthe pitch and roll, respectively. The sensor 158 produces a signal thatis transmitted to a controller 144. The controller 144 may be the samecontroller 44 described below for controlling the flow of liquids in thefluid storage and supply system 25 (FIG. 1) or may be a separatecontroller 144 that includes similar components (e.g., containsprocessors, memory and the like as described below).

The controller 144 controls the actuators 154A, 154B based on input fromthe sensor 158. Generally, the controller 144 controls the actuators154A, 154B to eliminate roll within the screen (i.e., the screen islaterally level). The controller 144 may control the actuators 154A,154B to achieve a target pitch of the screen 109. For example, thescreen 109 may be adjusted to have a positive pitch, negative pitch orto be level. The operator may select a pitch by a user interface (notshown) that is communicatively coupled to the controller 144.

Referring now to FIG. 17, in some embodiments, the pivot member 150 isaligned with the outlet 71 of the airlock 55 relative to the lateralaxis B (FIG. 3A) of the apparatus 3. The airlock outlet 71 has a width Wand the pivot member 150 is laterally aligned with the width W of theoutlet 71.

Alternatively or in addition, the pivot member 150 may be locatedrelatively near the airlock 55 relative to the longitudinal axis A (FIG.3A) such that the screen upon which material is loaded from the airlock55 pivots a relatively small amount near the airlock 55 which allows thevertical profile of the apparatus to be reduced. Referring now to FIG.14 in which a flat wire belt conveyor 133 is shown, the conveyor 133 hasa rear 170 toward which material is loaded onto the belt from theairlock outlet 71 and a front 172 toward which material is dischargedfrom the screen. A center plane E is midway between the rear 170 and thefront 172. The pivot member 150 is rearward to the center plane E of thescreen 133 relative to the longitudinal axis A (FIG. 3A) (i.e., thepivot member 150 is nearer the rear 170 than the front 172 of thescreen).

The airlock 55 has a bottom 175. The bottom 175 of the airlock 55 andthe rear 170 of the screen are separated by a distance D1 relative tothe longitudinal axis A (FIG. 3A). The bottom 175 of the airlock 55 andthe front 172 of the screen 133 are separated by a distance D2 relativeto the longitudinal axis A. The distance D1 between the bottom 175 ofthe airlock 55 and the rear 170 of the screen 133 is less than thedistance D2 between the bottom 175 of the airlock 55 and the front 172of the screen 133.

The pivot member 150 of the illustrated embodiment allows two degrees offreedom (e.g., roll and pitch) in which to adjust the screen. In someembodiments, the apparatus 3 does not include a panhard rod to eliminatea third degree of freedom (e.g., yaw).

Fluid Storage and Supply System

The hydro excavation vacuum apparatus 3 includes a fluid storage andsupply system 25 (FIG. 1) which supplies water for high pressureexcavation and stores water recovered from the dewatering system 95. Thefluid storage and supply system 25 includes a plurality of vessels 30for holding fluid. In the illustrated embodiment, the vessels 30 aresections of a baffled tank 32 (FIG. 18) with the vessels 30 beingseparated by baffles 35. The tank baffles 35 generally extend from thebottom 40 to the top 42 of each vessel 30 such that fluid does not passover the baffles 35 into adjacent vessels. In other embodiments, thevessels 30 are separate tanks. In some embodiments, water is notprocessed when transferred between tanks (e.g., further purificationsuch as by centrifugation in hydrocyclones or by addition of additivessuch as flocculants or coagulants).

In the embodiment illustrated in FIGS. 18-25, the fluid storage andsupply system 25 includes four vessels 30. In other embodiments, thesystem 25 may include two vessels 30 (FIG. 26), three vessels 30 (FIG.27) or more than four vessels 30 (e.g., five, six or more vessels).

The fluid storage and supply system 25 carries fluid used for highpressure excavation. As excavation of a site begins, the hydroexcavation vacuum apparatus 3 processes earth cuttings and reclaimedwater from the excavation site with reclaimed water being stored in thefluid storage and supply system 25. The initial water used forexcavation (i.e., water not having been processed through the dewateringsystem 95 of the apparatus 3) may be referred herein as “maiden water.”Water that has been reclaimed from the excavation site and stored in thefluid storage and supply system 25 may be referred to herein as “firstcycle water.” In some embodiments, first cycle water may be used as thesource of water for high pressure excavation. In such embodiments, thereclaimed water may be referred to as “second cycle water.” Additionalcycles may be performed to produce “third cycle water,” “fourth cyclewater,” and so on. The fluid storage and supply system 25 is adapted toallow maiden water to remain separated from first cycle water withouthaving dedicated empty tank space to reduce the volume of tanks carriedon the apparatus 3.

Referring now to FIG. 18, the fluid storage and supply system 25includes a first vessel 30A. The first vessel 30A is in fluidcommunication with the excavation fluid pump 6 (FIG. 3B). The system 25may include a first vessel pump 38A that may provide head pressure forthe excavation fluid pump 6 or that may be used to empty out the firstvessel 30A. In other embodiments, the first vessel pump 38A iseliminated. The fluid storage and supply system 25 also includes asecond vessel 30B that is in fluid communication with the dewateringsystem 95 to receive first cycle water discharged from the dewateringsystem 95. A return water pump 110 (FIG. 14) conveys first cycle waterfrom the catchpan 112 of the dewatering system 95 to the second vessel30B. The return water pump 110 may operate upon activation of a float ormay run continually to move first cycle water to the second vessel 30B.

A first vessel level sensor 36A measures the level of fluid in the firstvessel 30A and a second vessel level sensor 36B measures the level offluid in the second vessel 30B. A second vessel transfer pump 38B pumpsfluid from the second vessel 30B (e.g., to the first vessel 30A as intwo vessel embodiments or to a third vessel as in embodiments havingthree or more vessels).

As shown in FIG. 18, in some embodiments, the system 25 includes a thirdvessel 30C or even a fourth vessel 30D. The third vessel 30C is in fluidcommunication with the second vessel 30B. The second vessel transferpump 38B transfers fluid from the second vessel 30B into the thirdvessel 30C. A third vessel transfer pump 38C transfers fluid to thefirst vessel 30A or, in embodiments in which the system 25 includes afourth vessel, to the fourth vessel 30D. A third vessel level sensor 36Csenses the fluid level in the third vessel 30C.

In embodiments in which the fluid storage and supply system 25 includesa fourth vessel 30D, the fourth vessel 30D is in fluid communicationwith the third vessel 30C. A fourth vessel level sensor 36D senses thefluid level in the fourth vessel 30D. A fourth vessel transfer pump 38Dtransfers fluid from the fourth vessel 30D to the first vessel 30A.

The level sensors 36A, 36B, 36C, 36D may be ultrasonic sensors, radarsensors, capacitance sensors, float sensors, laser sensors or the like.

The vessels 30 of the fluid storage and supply system 25 may be separatecompartments of a single tank as shown in FIGS. 18-27 or may be separatetanks or may be a combination of compartmentalized tanks and separatetanks.

Cycling of water within the fluid storage and supply system 25 isillustrated in FIGS. 19-25. While cycling of water in the system 25 maybe described and shown with reference to four vessels 30, thedescription is also applicable to two or three vessel systems unlessstated differently.

To perform an excavation, the first vessel 30A and, if equipped and asin the embodiment of FIG. 19, the third vessel 30C, and fourth vessel30D, are filled with maiden water 50, indicated by stippling. The sourceof maiden water may be potable water, surface water (e.g., pond, river,ditch water) or grey water substantially fee of abrasive grit. Afterfilling, the maiden water 50 in the first vessel 30A has an initiallevel. The hydro vacuum excavating apparatus 3 is then transported fromthe site at which the vessels are filed with maiden water to a secondsite at which a high-pressure water excavation is performed. Duringexcavation of a site, the excavation fluid pump 6 (FIG. 3B) directshigh-pressure maiden water through the wand 4 (FIG. 3C). Duringexcavation, the vacuum system 7 (FIG. 1) causes spoil material to becomeentrained in an airstream and pass through the boom 9 and other conduitsand into the separation vessel 21. Spoil material is separated from theairstream by the separation vessel 21 and cyclones 11. The spoilmaterial is introduced into the dewatering system 95 through airlock 55and/or pumped from the cyclone discharge pump 20. The first cycle wateris separated from spoil material in the dewatering system 95. Theseparated first cycle water is directed to the second vessel 30B. Solidsdischarged from the dewatering system 95 falls into a hopper 125(FIG. 1) and are conveyed from the hopper 125 by a conveyor assembly 127to form a stack of solids.

As excavation commences, maiden water 50 is drawn from the first vessel30A causing the level of fluid in the first vessel 30A to be reducedbelow the initial level (FIG. 20). The first vessel level sensor 36Asenses the reduction in the fluid level in the first vessel 30A. Oncethe level of maiden water in the first vessel 30A is reduced to belowthe initial level or is even reduced further (e.g., reduced to a levelof about 99% of the initial level or less, about 95% or less, about 90%or less, about 50% or less, about 25% or less, about 10% less or whenthe first vessel 30A is emptied of maiden water 50), additional maidenwater 50 is transferred to the first vessel 30A. For example, maidenwater may be pumped from the fourth vessel 30D into the first vessel 30Ato maintain a level of fluid in the first vessel 30A for excavation. Inembodiments in which the system 25 includes three vessels (FIG. 27),maiden water may be pumped from the third vessel 30C into the firstvessel 30A.

In this manner, additional maiden water may be directed toward theexcavation site after the volume of the maiden water used for excavationis at least the volume of the first vessel 30A (i.e., additionalexcavation may be performed after the volume of maiden water in thefirst vessel 30A is consumed). Water may be transferred within thesystem 25 as excavation is being performed and the dewatering system 95operates.

As maiden water 50 is transferred from the fourth vessel 30D into thefirst vessel 30A, the level of fluid in the fourth vessel 30D isreduced. As the level of fluid in the fourth vessel 30D is reduced tobelow the initial level or less (e.g., to a level of about 99% of theinitial level or less, or about 95% or less, about 90% or less, about50% or less, about 25% or less, about 10% less or when the fourth vesselis emptied of maiden water), maiden water from the third vessel 30C istransferred to the fourth vessel 30D (FIG. 21).

During excavation, the empty second vessel 30B begins to fill with firstcycle water 53, shown with heavier stippling in FIG. 20. The secondvessel 30B continues to fill with first cycle water 53 (FIG. 22) asexcavation continues. After the third vessel 30C is emptied of maidenwater (FIG. 22), first cycle water 53 is transferred from the secondvessel 30B into the third vessel 30C (FIG. 23). Once the fourth vessel30D is emptied of maiden water 50, first cycle water 53 from the thirdvessel 30C may be pumped to the fourth vessel 30D (FIG. 24).

After the maiden water in the fluid storage and supply system 25 isconsumed, first cycle water may be used for excavation. The first cyclewater 53 may be transferred into the first vessel 30A (FIG. 25). Theexcavation fluid pump 5 (FIG. 3B) directs pressurized first cycle water53 from the first vessel 30A toward an excavation site to cut earthenmaterial. The cut earth and first cycle water (now second cycle water)are removed from the excavation site. The second cycle water isseparated from the cut earthen material in the dewatering system 95(FIG. 1) with the second cycle water being introduced into the secondvessel 30B. As excavation continues, the second cycle water issubsequently introduced into the third vessel 30C, fourth vessel 30D,and/or first vessel 30A. After first cycle water is consumed, the secondcycle water may be used for excavation by transferring second cyclewater into the first vessel 30A. The excavation fluid pump 6 directspressurized second cycle water from the first vessel 30A toward anexcavation site. Additional cycles may be performed to re-use reclaimedwater and reduce the frequency at which maiden water is loaded onto theapparatus.

In some embodiments, the fluid processed through the dewatering system95 (e.g., first cycle water, second cycle water, etc.) and stored in thefluid storage and supply system 25 is monitored to determine if thefluid is suitable for use for excavation. The fluid may be monitoredmanually or automatically. The fluid may be monitored by measuringclarity, translucence, conductivity, viscosity, specific gravity, or thelike. Fluid that is unsuitable for excavation may be disposed (e.g.,municipal water treatment) or may be treated in a separate reclamationsystem (e.g., with coagulant or flocculant treatment). An examplereclamation system is disclosed in U.S. Provisional Patent ApplicationNo. 62/444,567, filed Jan. 10, 2017, entitled “Systems and Methods forDosing Slurries to Remove Suspended Solids,” which is incorporatedherein by reference for all relevant and consistent purposes.

Another embodiment of the fluid storage and supply system 25 is shown inFIGS. 38 and 39. The system 25 generally includes the components of thesystem described above with several differences being described below.As shown in FIG. 39, the drive motor 34 of each pump 38 (first motor 34Aand first vessel pump 38A being shown in FIG. 39) is disposed above thevessel 30A. The bottom 40 of each vessel 30 angles downward toward thepump 38 to allow the vessels to be more fully emptied. At least one ofthe vessels 30 such as the first vessel 30A (FIG. 39) includes an airgapdevice 132 as shown in FIG. 40 to prevent siphoning andcross-contamination through the transfer pipes 120.

Referring now to FIG. 41, the system 25 includes a discharge manifold107 for offloading water from the system 25 (e.g., recycled water suchas first cycle water, second cycle water or the like). The system 25includes valves 45A, 45B, 45C, 45D that are actuated to selectively movewater within the system. During excavation and during recovery of waterfrom the earthen slurry, the first valve 45A is positioned to directmaiden water discharged from the first vessel pump 38A to the excavationpump 6 (FIG. 3B). The second, third, and fourth valves 45B, 45C, 45D arepositioned to direct water (e.g., maiden water or recycled waterdepending on how much maiden water and recycled water is in the system)to the next vessel in the system 25. To drain any of the vessels 30A,30B, 30C, 30D with water, the corresponding valve 45A, 45B, 45C, 45D maybe positioned such that water drains into the discharge manifold 107.The discharge manifold 107 includes an outlet through which water mayexit the system 25.

In some embodiments, the discharge manifold 107 may be used whilefilling the system 25 with maiden water. For example, maiden water isdirected into the first vessel 30A (FIG. 38) through airgap device 132.The first pump 38A is operated and the valve 45A is positioned to directmaiden water from the first vessel 30A to the discharge manifold 107(FIG. 41). The outlet of the discharge manifold is closed such that themanifold 107 fills with water. The third and fourth vales 45C, 45D arepositioned to allow maiden water to flow from the manifold 107, throughpumps 38C, 38D (i.e., pumps 38C, 38C are off and water is caused toback-flow through pumps 38C, 38D). In this manner the first, third andfourth vessels 30A, 30C, 30D can be filled with maiden water. The secondvalve 45B is positioned such that the second tank 30B is not in fluidcommunication with the manifold 107 to allow the second tank 30B toremain empty to receive first cycle water. The system 25 may beautomated by controlling the first pump 38A to cause the first, thirdand fourth vessels 30A, 30C, 30D to be at or near the same level duringfilling (e.g., by use of level sensors 36A, 36C, 36D).

Referring now to FIG. 42, each valve 45 includes a plunger 111. In thelowered position, the plunger 111 directs fluid that is received fromthe transfer pump in transfer pump conduit 115 to the transfer pipe 120that is in fluid communication with the next vessel in the system 25 orwith the excavation pump 6 (FIG. 3B). In the raised position of theplunger 111, fluid is directed from the transfer pump conduit 115 to thedischarge conduit 124 which is connected to the discharge manifold 107(FIG. 40) (or flows in the reverse direction such that maiden waterflows from the manifold 107 to the tanks 30C, 30D such as when fillingthe system 24 with maiden water). In the illustrated embodiment, thevalve 45 is actuated by hand by lever 130. In other embodiments,actuation of each valve 45 is automated.

In some embodiments, the fluid storage and supply system 25 includes acontroller 44 (FIG. 28) that enables the second vessel transfer pump38B, third vessel transfer pump 38C, and/or the fourth vessel transferpump 38D to operate based at least in part on an output signal from thefirst vessel level sensor 36A, second vessel level sensor 36B, thirdvessel level sensor 36C, and/or fourth vessel level sensor 36D.

The controller 44 is communicatively coupled to the second vesseltransfer pump 38B, third vessel transfer pump 38C, and the fourth vesseltransfer pump 38D. The controller 44 selectively powers the pumps 38B,38C, 38D to move maiden water and first cycle water within the vessels30A, 30B, 30C, 30D as discussed further herein. The controller 44 mayalso be communicatively or operatively coupled to the first vessel pump38A (e.g., to operate the pump 38A when the excavation pump 6 isoperating or to unload all fluid from the first vessel 30A).

The controller 44 may control the pumps 38B, 38C, 38D based oninstructions stored in a memory device (not shown), input received fromsensors 36A, 36B, 36C, 36D, input from a user via a user interface,and/or input received from any other suitable data source.

Controller 44, the various logical blocks, modules, and circuitsdescribed herein may be implemented or performed with a general purposecomputer, a digital signal processor (DSP), an application specificintegrated circuit (ASIC), a field programmable gate array (FPGA), orother programmable logic device, discrete gate or transistor logic,discrete hardware components, or any combination thereof designed toperform the functions described herein. Example general purposeprocessors include, but are not limited to only including,microprocessors, conventional processors, controllers, microcontrollers,state machines, or a combination of computing devices.

Controller 44 includes a processor, e.g., a central processing unit(CPU) of a computer for executing instructions. Instructions may bestored in a memory area, for example. Processor may include one or moreprocessing units, e.g., in a multi-core configuration, for executinginstructions. The instructions may be executed within a variety ofdifferent operating systems on the controller, such as UNIX, LINUX,Microsoft Windows®, etc. It should also be appreciated that uponinitiation of a computer-based method, various instructions may beexecuted during initialization. Some operations may be required in orderto perform one or more processes described herein, while otheroperations may be more general and/or specific to a particularprogramming language e.g., and without limitation, C, C#, C++, Java, orother suitable programming languages, etc.

Processor may also be operatively coupled to a storage device. Storagedevice is any computer-operated hardware suitable for storing and/orretrieving data. In some embodiments, storage device is integrated incontroller. In other embodiments, storage device is external tocontroller and is similar to database. For example, controller mayinclude one or more hard disk drives as storage device. In otherembodiments, storage device is external to controller. For example,storage device may include multiple storage units such as hard disks orsolid state disks in a redundant array of inexpensive disks (RAID)configuration. Storage device may include a storage area network (SAN)and/or a network attached storage (NAS) system.

In some embodiments, processor is operatively coupled to storage devicevia a storage interface. Storage interface is any component capable ofproviding processor with access to storage device. Storage interface mayinclude, for example, an Advanced Technology Attachment (ATA) adapter, aSerial ATA (SATA) adapter, a Small Computer System Interface (SCSI)adapter, a RAID controller, a SAN adapter, a network adapter, and/or anycomponent providing processor with access to storage device.

Memory area may include, but are not limited to, random access memory(RAM) such as dynamic RAM (DRAM) or static RAM (SRAM), read-only memory(ROM), erasable programmable read-only memory (EPROM), electricallyerasable programmable read-only memory (EEPROM), and non-volatile RAM(NVRAM). The above memory types are exemplary only, and are thus notlimiting as to the types of memory usable for storage of a computerprogram.

In some embodiments, the fluid storage and supply system 25 includes avalving system 48 (FIG. 29) for switching the source of water used forhigh pressure excavation from vessel to vessel. The valving system 48allows one of the first vessel 30A, 30B, 30C, 30D to be in fluidcommunication with the fluid excavation pump 6 and wand 4. In thismanner, additional maiden pressurized water may be directed toward theexcavation site after the volume of the maiden pressurized water usedfor excavation is at least the volume of the first vessel 30A (i.e.,additional excavation may be performed after the volume of maiden waterin the first vessel 30A is consumed). The valving system 48 may includehand-operated valves for switching the source of water used forexcavation or the system 48 may include a controller (not shown) whichcontrols the valving system 48 based on, at least in part, a signal fromat least one of the first vessel level sensor 36A, the second vessellevel sensor 36B, the third vessel level sensor 36C, and the fourthvessel level sensor 36D.

Alternatively or in addition, a valving system (not shown) may be usedto select which vessel 30A, 30B, 30C, 30D is filled with first cyclewater (i.e., a valving system disposed between the dewatering system 95and the fluid storage and supply system 25). Alternatively or inaddition, a valving system (not shown) may be used to transfer fluidbetween vessels 30A, 30B, 30C, 30D.

In some embodiments of the present disclosure, the hydro excavationvacuum apparatus is a mobile apparatus capable of recycling the waterused for excavation such that the apparatus may be used to excavate oneor more sites during daily use (e.g., for 8, 10 or 12 or more hours)without re-filling with maiden water and/or disposing of reclaimedwater. The apparatus 3 may include vessels that are filled with maidenwater before excavation begins with relatively little empty tank space(e.g., with 1250 gallon, 1500 gallon, 1750 gallon or more maiden watercarrying capacity). The system may generate a vacuum of at least 18″ Hgat 3000 standard cubic feet per minute. The dwell time of air passingthrough the separation vessel 21 may be less than about 5 seconds. Avibratory screen used to separate solids may have openings of 250microns or less.

Compared to conventional apparatus for hydro vacuum excavating a site,the apparatus of the present disclosure has several advantages. Thesystem may be adapted to process larger solids such as solids generatedwhen a rotary wand is used to excavate a site (e.g., solids with anominal diameter up to the size of the vacuum system conduits such as upto 6″). The system may include a deceleration system having adeceleration vessel and deflection plate which allows solids to bequickly directed toward the airlock. The deceleration vessel allows alarge volume of air and cut earth and water to be processed in arelatively compact vessel which reduces the footprint of the separationvessels to be reduced. The deceleration vessel may be more compact thana cyclone in which materials are vortexed as the cyclone should have asufficiently large spoil material outlet to let larger solids to passbut typically only operate efficiently within a small range of length todiameter ratios. In some embodiments, a single deceleration vessel maybe used which further reduces cost and the footprint of the dewateringsystem.

In embodiments in which the dwell time of air passing through theseparation vessel is relatively small (e.g., less than about 5 seconds,3 seconds or even 1 second or less), the solid material contacts liquidfor a relatively small amount of time which reduces absorption of liquidby the solid particles which allows the particles to more easily travelover screens in downstream screening operations and allows at least somematerial to be processed before becoming a slurry which reduces waterusage. Reducing dwell time also allows the size of the separation vesselto be reduced which reduces size and weight of the apparatus. Inembodiments in which the airlock discharges directly to the dewateringscreens of the dewatering system without intermediate processing (e.g.,without centrifugation), the amount of time the solid earthen materialcontacts liquid may be further reduced which improves separation ofsolids from the liquid.

In embodiments in which the airlock has an outlet that tapers outwardlyfrom a vertex, air may be pulled into the airlock near the vertex at arelatively high velocity, which causes the cut earthen material andwater resting on the vane rotating into the opening to be agitated whichpromotes material to fall from the vane.

In embodiments in which the airlock includes a relatively small numberof vanes (e.g., less than 15 or less than 10) and corresponding pockets,relatively large solids may be processed through the airlock. The numberof vanes and the vane length may be selected to allow the pockets toaccommodate the largest size of cut earthen material that may fitthrough the vacuum conduit. In embodiments in which the airlock rotatesrelatively slowly (e.g., less than 10 RPM), the amount of air thatpasses into the airlock into the vacuum system may be reduced.

In some embodiments, the vacuum system includes a positive displacementvacuum pump to increase the capacity and the vacuum generated by thesystem to allow larger solids to be processed (e.g., generating a vacuumof at least 18″ Hg at 3000 cubic feet per minute).

In embodiments in which the apparatus includes a fluid storage andsupply system with a plurality of vessels in which maiden water and/orfirst cycle water is cycled through the vessels or includes a valvingsystem to change the vessel from which excavation water is pulled,maiden water may remain separated from first cycle water with a reducedamount of tank space on the apparatus (e.g., a reduced amount of emptytank space after filling with maiden water before excavation has begun).

In embodiments in which the dewatering system includes a pre-screen thatseparates larger solids before the spoil material contacts a downstreamvibratory screen (e.g., a pre-screen with large openings such the ratioof the size of the pre-screen openings to the size of the openings ofthe vibratory screen is at least about 100:1), the downstream vibratoryscreen may be protected from impact with the large solids which reducesdamage and fouling of the vibratory screen.

In embodiments in which the system includes a pitch and roll adjustmentsystem with a pivot member that is laterally aligned with the outlet ofthe airlock, rolling of the screen (e.g., pre-screen, vibratory screen,or flat wire belt conveyor) caused by impact of material onto the screenis reduced or eliminated. In embodiments in which the pivot member ispositioned rearward to a center plane of the screen (i.e., closer to therear of the screen), the screen moves less near the airlock when thepitch of the screen is adjusted. This allows for less clearance betweenthe screen and airlock and the vertical profile of the apparatus may bereduced. This also allows the spoil material to travel along a longerlength of the screen which promotes separation of water from the spoilmaterial.

By processing spoil material onboard the apparatus, solid materials maybe separated to allow the spoil material (e.g., first pass water) to bemore efficiently stored on the apparatus due to the smaller volume ofthe material. Separating solids allows the recovered water to be usedfor excavation in one or more cycles. Separated solids may be used forbackfilling the excavation site which reduces the cost of the excavationoperation and allows for efficient use of solids.

In embodiments in which the cyclonic separation system includesconveyors below the cyclones for removing material, the conveyors canremove material from the solids outlet of the cyclones which reduces orprevents pluggage of the cyclone outlets. Use of sealed conveyors andperistaltic pumps prevents air from entering the system from the ambientatmosphere.

In embodiments in which the fluid storage and supply system includes amanifold connected to the vessels of the system and valves that may beactuated to allow the vessels to be filled from the manifold, the firstvessel pump may be operated to quickly fill additional tanks with maidenwater through the manifold. Use of an airgap device preventscontamination of maiden water through back-flow.

As used herein, the terms “about,” “substantially,” “essentially” and“approximately” when used in conjunction with ranges of dimensions,concentrations, temperatures or other physical or chemical properties orcharacteristics is meant to cover variations that may exist in the upperand/or lower limits of the ranges of the properties or characteristics,including, for example, variations resulting from rounding, measurementmethodology or other statistical variation.

When introducing elements of the present disclosure or the embodiment(s)thereof, the articles “a”, “an”, “the” and “said” are intended to meanthat there are one or more of the elements. The terms “comprising,”“including,” “containing” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements. The use of terms indicating a particular orientation (e.g.,“top”, “bottom”, “side”, etc.) is for convenience of description anddoes not require any particular orientation of the item described.

As various changes could be made in the above constructions and methodswithout departing from the scope of the disclosure, it is intended thatall matter contained in the above description and shown in theaccompanying drawing[s] shall be interpreted as illustrative and not ina limiting sense.

What is claimed is:
 1. A hydro excavation vacuum apparatus forexcavating earthen material comprising: a wand for directing pressurizedwater toward earthen material to cut the earthen material at anexcavation site; a vacuum system for removing cut earthen material andwater from the excavation site in an airstream; a separation vessel forremoving cut earthen material and water from the airstream; an airlockthat receives material from the separation vessel and discharges thematerial through an airlock outlet; and a dewatering system forseparating water from cut earthen material discharged from the airlockoutlet, the dewatering system comprising: a pre-screen that receivesmaterial from the outlet of the airlock, the pre-screen having openingsfor separating material from the separation vessel by size; and avibratory screen for separating material that passes through thepre-screen by size, the vibratory screen having openings sized smallerthan the openings of the pre-screen.
 2. The hydro excavation vacuumapparatus as set forth in claim 1 wherein the pre-screen has openings ofat least about 0.5 inches.
 3. The hydro excavation vacuum apparatus asset forth in claim 1 wherein a ratio of the size of the openings of thepre-screen to the size of the openings of the vibratory screen is atleast about 100:1.
 4. The hydro excavation vacuum apparatus as set forthin claim 1 wherein the vibratory screen has openings of less than 250micron.
 5. The hydro excavation vacuum apparatus as set forth in claim 1further comprising a shaker assembly comprising the vibratory screen,the shaker assembly adapted to move the vibratory screen linearly or inan elliptical path.
 6. The hydro excavation vacuum apparatus as setforth in claim 1 wherein the rotary nozzle comprises a rotor inserthaving blades that rotate around a longitudinal axis of the nozzle whenwater is forced through the nozzle.
 7. The hydro excavation vacuumapparatus as set forth in claim 1 wherein the vacuum system comprises avacuum pump, the vacuum pump being a positive displacement pump.
 8. Thehydro excavation vacuum apparatus as set forth in claim 1 wherein thevacuum system comprises a vacuum pump, the vacuum pump being capable ofgenerating a vacuum of at least 18″ Hg at 3000 cubic feet per minute. 9.The hydro excavation vacuum apparatus as set forth in claim 8 whereinthe vacuum system comprises: a boom for entraining material from theexcavation site into the air stream; and one or more conduits thatfluidly connect the boom to the separation vessel, the one or moreconduits having a diameter of 6 inches or less.
 10. The hydro excavationvacuum apparatus as set forth in claim 1 further comprising: a chassisfor supporting the vacuum system, separation vessel, airlock and/ordewatering system; and wheels attached to the chassis for transportingthe hydro excavation vacuum apparatus between sites.
 11. The hydroexcavation vacuum apparatus as set forth in claim 1 wherein theapparatus does not include hydrocyclones for separating water fromearthen material.
 12. The hydro excavation vacuum apparatus as set forthin claim 1 wherein the wand comprises a rotary nozzle for directingwater in a rotating, circular path toward the earthen material at theexcavation site.
 13. A hydro excavation vacuum apparatus for excavatingearthen material comprising: a wand for directing pressurized watertoward earthen material at an excavation site to cut the earthenmaterial; a vacuum system for removing cut earthen material and waterfrom the excavation site in an airstream, the vacuum being capable ofgenerating a vacuum of at least 18″ Hg at 3000 cubic feet per minute; aseparation vessel for removing cut earthen material and water from theairstream; an airlock that receives material discharged from theseparation vessel and discharges the material through an airlock outlet;and a dewatering system for separating water from cut earthen materialdischarged from the airlock outlet.
 14. The hydro excavation vacuumapparatus as set forth in claim 13 wherein the wand comprises a rotarynozzle for directing water in a rotating, circular path toward theearthen material at the excavation site.
 15. The hydro excavation vacuumapparatus as set forth in claim 13 wherein the dewatering systemcomprises: a pre-screen that receives material from the separationvessel, the pre-screen having openings of at least about 0.5 inches forseparating material from the separation vessel by size; and a vibratoryscreen for separating material that passes through the pre-screen bysize, the vibratory screen having openings with a size smaller than thesize of the openings of the pre-screen, a ratio of the size of theopenings of the pre-screen to the size of the openings of the vibratoryscreen being at least about 100:1.
 16. The hydro excavation vacuumapparatus as set forth in claim 15 wherein a ratio of the size of theopenings of the pre-screen to the size of the openings of the vibratoryscreen is at least about 250:1.
 17. The hydro excavation vacuumapparatus as set forth in claim 15 wherein the vibratory screen hasopenings of less than 250 micron.
 18. The hydro excavation vacuumapparatus as set forth in claim 13 wherein the vacuum system comprises avacuum pump, the vacuum pump being a positive displacement pump.
 19. Thehydro excavation vacuum apparatus as set forth in claim 13 wherein theapparatus does not include hydrocyclones for separating water fromearthen material.